Gel Battery? Best Battery for a bike parked at an airport?

For ease of travel, I have a bike stored outside at an airport and I use it about every 2 months.
At the moment the bike has a traditional standard lead/acid battery in it.
As the battery is not new, I figure it is only a matter of time before it becomes sulfated and and can no longer be used.
I was therefore considering a GEL battery as a replacement and I am wondering if these would last longer under such conditions?